1. Field of the Invention
The present invention relates to an image input-output apparatus of the type which has a common transfer path for selectively transferring a document and a recording paper.
2. Description of the Related Art
An example of image input-output apparatus is a multifunction apparatus which provides an image reading function and an image printing function under the control of an outside computer such as personal computer. Another example of image input-output apparatus is a facsimile machine.
There are two types of image input-output apparatuses. A first type of image input-output apparatus has two different transfer paths for separately transferring a document and a recording paper, wherein an image reader is provided along the document transfer path while a printing unit is provided along the recording paper transfer path. A second type of image input-output apparatus has a common transfer path for selectively transferring a document and a recording paper, wherein an image reader and a printing unit are equally arranged long the common transfer path.
In either type of the image input-output apparatuses described above, a document width detector is provided in a document container for detecting the width of the document, whereas a recording paper width detector is provided in a recording paper container for detecting the width of the recording paper. Therefore, the need for providing the two separate width detectors increases the manufacturing cost of the image input-output apparatus as a whole while also increasing the total number of required components to result in increasing the assembly steps.